# -*- coding: utf-8 -*-
"""
Tencent is pleased to support the open source community by making 蓝鲸智云PaaS平台社区版 (BlueKing PaaS Community
Edition) available.
Copyright (C) 2017-2020 THL A29 Limited, a Tencent company. All rights reserved.
Licensed under the MIT License (the "License"); you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://opensource.org/licenses/MIT
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
specific language governing permissions and limitations under the License.
"""

from django.dispatch import Signal
from django.utils.deprecation import MiddlewareMixin

from blueapps.conf import settings
from blueapps.core.exceptions import AccessForbidden, ServerBlueException

# since each thread has its own greenlet we can just use those as identifiers
# for the context.  If greenlets are not available we fall back to the
# current thread ident depending on where it is.
try:
    from greenlet import getcurrent as get_ident
except ImportError:
    try:
        from thread import get_ident
    except ImportError:
        from _thread import get_ident


class AccessorSignal(Signal):
    allowed_receiver = "blueapps.utils.request_provider.RequestProvider"

    def __init__(self, providing_args=None):
        Signal.__init__(self, providing_args)

    def connect(self, receiver, sender=None, weak=True, dispatch_uid=None):
        receiver_name = ".".join(
            [receiver.__class__.__module__, receiver.__class__.__name__]
        )
        if receiver_name != self.allowed_receiver:
            raise AccessForbidden(u"%s is not allowed to connect" % receiver_name)
        Signal.connect(self, receiver, sender, weak, dispatch_uid)


request_accessor = AccessorSignal()


class RequestProvider(MiddlewareMixin):
    """
    @summary: request事件接收者
    """

    _instance = None

    def __new__(cls, get_response):
        if cls._instance is None:
            cls._instance = super(RequestProvider, cls).__new__(cls)
        return cls._instance

    def __init__(self, get_response):
        super(RequestProvider, self).__init__(get_response)
        self._request_pool = {}
        request_accessor.connect(self)

    def process_request(self, request):
        request.is_mobile = lambda: bool(
            settings.RE_MOBILE.search(request.META.get("HTTP_USER_AGENT", ""))
        )

        # 是否为合法的RIO请求
        request.is_rio = lambda: bool(
            request.META.get("HTTP_STAFFNAME", "")
            and settings.RIO_TOKEN
            and settings.RE_WECHAT.search(request.META.get("HTTP_USER_AGENT", ""))
        )

        # 是否为合法 WEIXIN 请求，必须符合两个条件，wx 客户端 & WX PAAS 域名
        request_origin_url = "{}://{}".format(request.scheme, request.get_host())
        request.is_wechat = lambda: (
            bool(settings.RE_WECHAT.search(request.META.get("HTTP_USER_AGENT", "")))
            and request_origin_url == settings.WEIXIN_BK_URL
            and not request.is_rio()
        )

        # JWT请求
        request.is_bk_jwt = lambda: bool(request.META.get("HTTP_X_BKAPI_JWT", ""))

        self._request_pool[get_ident()] = request
        return None

    def process_response(self, request, response):
        assert request is self._request_pool.pop(get_ident())
        return response

    def __call__(self, *args, **kwargs):
        """
        1）接受 signal 请求响应，
        2）继承 MiddlewareMixin.__call__ 兼容 djagno 1.10 之前中间件
        """
        from_signal = kwargs.get("from_signal", False)
        if from_signal:
            return self.get_request(**kwargs)
        else:
            return super(RequestProvider, self).__call__(args[0])

    def get_request(self, **kwargs):
        sender = kwargs.get("sender")
        if sender is None:
            sender = get_ident()
        if sender not in self._request_pool:
            raise ServerBlueException(u"get_request can't be called in a new thread.")
        return self._request_pool[sender]


def get_request():
    return request_accessor.send(get_ident(), from_signal=True)[0][1]


def get_x_request_id():
    x_request_id = ""
    http_request = get_request()
    if hasattr(http_request, "META"):
        meta = http_request.META
        x_request_id = (
            meta.get("HTTP_X_REQUEST_ID", "") if isinstance(meta, dict) else ""
        )
    return x_request_id
